Artificial limb



c;L E. s'rEELE ET A1.

ARTIFICIAL LIIIB Filed Feb/16, 19:57

3 Sheets-Sheet 2 Aug. 22, 1939. c. E. STEELE Er Al.

ARTIFIcIAn mu 3 Sheets-'Sheet 5 s E nTK c SE ALEB 5 Rm AA HJ C m 9 1 6, l b. e F d w. .1 F

' UNITED STATES Patented'Aug. 22, 1939 PATENT. oFFlcE Application February 1s, issmseriai No. 125,984

6 Claims.

Our invention relates in general to artificial limbs, and in particular to that type of limb specially adapted to cases where the leg of the wearer has been amputated above the knee.

It is well known to those skilled in the art that. 1n order to closely approximate, in an artificial limb, the actual action and limb, it is necessary that the ,use of a natural re be a free movetion to provide an artificial limb formed withmeans for normally locking t he parts thereof in rigid position when in alignment and, at the same time, permitting bending at the knee, when desired, by means of the weight Moreover, our invention obviates all shoulder strap actuation and, therefore, permits the wearer to more closely approximate the natural movements of walking.

of the wearer.

Furthermore, our device is *of` such a nature that the limb portions will be l ing the f orward step of the normal act of walking.

Moreover, our device permits the wearer to eas11y unlock the parts so as to make it easy and convenient for the wearer to bend our artificial limb at the knee when sittin Moreover, our device is not only simple and cheap to manufacture, but gives to the wearer ockedtogether durwearer and before` any weight is placed thereon, whereby collapse or buckling at the knee j oint is impossible in the g down.

perfect confidence and ease whenbeing worn.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings, cf which:

Figs. .1, 2, and 3 show three positions of our artificial limb when the wearer is taking a forward step, a part Cf the thigh portion being broken away. f

Fig. 4 is an enlarged,

Fig. 5 is a similar view showing the locking means released and the parts bent at the knee, as

fragmentary, longitudinal, sectional elevation of our device taken on a lineI along one side of the longitudinal center thereof, partially indicated by the line 4-4 of Fig. 6, a part of the thigh portion being broken corresponding generally to the dotted line posivtion of Fig. 3, parts of the t tions 4being broken away,

high .ang calf por- (cl. 3 2) l Fig. 6 is a fragmentary, enlarged elevation showing a rear view of our invention.

Fig. '7 is an enlarged, perspective view of the lock latch of the form of our invention shown in Figs. 4 to 6, inclusive.

Fig. 8 is a fragmentary, longitudinal, sectional view of a modified form of invention taken on a line at one side of the longitudinal center of the devize and partially indicated by line 8-8 oi' Fig. 10. v

Fig. 9 is asimilar view showing positions taken by the latch means and associated parts during the operation of bending the device at the knee, portions o'f the limb being broken away for clearness of illustration.

Fig. 10 is a fragmentary, rear view of the form of invention shown in Figs. 8 and 9. Fig. 11 is a fragmentary, longitudinal, sectional elevation of another form of our invention and is taken on a line at one side of the longitudinal center thereof, partially indicated by the line H-ll of Fig. 13.

Fig. 12 is a similar view showing the positions assumedby the parts when bent at the knee.

Fig. 13 is a fragmentary, rear elevation of the 25 form of invention shown in Figs. 11 and 12.

In all the forms of our invention herein shown and described, the means for' causing the thigh and calf portions of the limb to be locked in alignment comprises a movable strut member or supplemental wall portion engageable with the rear wall parts of said thigh and calf portions and, when 'so engaged, being disposed. Within a space provided between said rear wall parts, whereby the load is transmitted to and ,through the limb parts.A In each form lof the invention means are also provided for yieldably urging said strut member or supplemental wall *portiony to its load-supporting position. e

Referring now particularly to the form of invention shown in Figs. 1 to 7, inclusive, I5 is the thigh portion, and I6 the calf portion which is pivoted to` the thigh portion by means of a 'pivot Il, preferably carried by the calf portion 'and pivoted in suitablebearings carried by the thigh portion. A foot portion I8 is provided in our invention which is. connected to the calf portion by means of the pivot I9. This pivot is connected to the calf portion by means of a bolt 20 and to the foot portion by means of a bolt 2|. .50 A limited ankle movement between the foot portion and the calf portion is thus made possible, which movement is resisted by meansof resilient inserts 22 arrangedl between the lower part of '.the calf port. )n and the foot portion. 55

tion by means of a resilient strap 26. The strap i extends upwardly and has its upper end fastened to a staple member 21 .which issuitably secured to the calf portion, as shown. The resilient strap 2B is vplaced under slight tension and serves to maintain the calf portion andthe thigh portion in the positions shown in Fig. 4 and to bring them back to such position when the calf portion is bent at the kneeI joint, as shown in Fig. 5. It will be obvious from Fig. 5 that when the calf portion is bent at the knee joint, the backstop will be moved downwardly into the calf portion and thus produce additional tension upon the resilient strap 26. The thigh portion carries a suitable pad 28 for engaging the forward surface of vthe backstop 25, and the calf portion i6 alsocarries a pad 29 for engagement with the opposite side of the backstop. This backstop prevents the calf portion i6 from swinging forwardly on the pivot i1 beyond a predetermined point.

Carried by the backstop 25 is a lock latch 3D,

which latch together with the backstop forms av strut member between the thigh and` calf portions when in alignment. This lock latch comprises two interspaced side arms 3i which are connected together by cross bars 32 (see Fig. '1) The latch is so mounted that the arms` thereof straddle the backstop 25 andare thus located one on each side of the backstop. At the upper end of each.A of the side arms there is provided a lock arm 33 which is arranged substantially at right angles to the side arm and which extends rearwardly so as to be engageable with the upper surface of the abutment 34 of a strip of wearing material 35 which is secured to the usual wood structure of the back wall of the calf portion i 6, as clearly shown in Figs.l 4 and 6.

Arranged inside of the calf portion and opposite the location of the backstop and lock latch` is a control lever 36 having an upwardly extending arml 31 and a forwardly extending arm 38 arranged preferably at right angles to the arm 31. This control lever is mounted upon av pivot 23 carried by a stud 39 supported by the forward part of the calf portion of the limb and arranged a slight distance above the forwardly extending arm 38. The upper arm 31 of this control lever is connected to the upper end of one of the side arms 3| of the lock latch by means of a latch rod 40 and a latch link 4I. The latch rod is preferably screwthreaded to the latch link so that adjustment of the distance between' the lock latch and the arm 31'may be conveniently made. The lock latch is kept normally in the position shown in Fig. 4 by means vof a `helical spring 48 which has one of its ends connected to the upper arm 31 of the control lever and its other end suitably secured toa bolt 49 carried by the rear part of the calf portion.

The forwardly extending arm 38 of the control lever is connected to the heei42 of the foot portion I8 of our device by means of a contrl 10d 43 and a control link 44. This rod and the link are pivotally connected at 45 and the lower end of the rod 43 is passed through a suitable aperture 46 in the lower part of the calf portion and its lower end is provided with a nut 41 whereby, when the foot portion is moved about its pivot as the weight of the wearer is placed upon the toe thereof, the control rod 43 and the control lever 44 will be pulled downwardly, thus actuating the lock latch 30.

From the foregoing it will be obvious that when the thigh portion and calf portion are in the relative positions shown in Fig. 4, which are the same positions as those occupied in Fig. 1 where the limb has been moved forwardly in the act of taking a step, they have been brought into alignment and securely locked together. When the weight of the wearer is now placed upon the heel 42 (see Fig. l), the foot portion i8 will be moved on the pivot i9 to simulate the action of a natural foot. The weight of the wearer upon the heel will, however, not affect the locking engagement of the limb portions. The vertical movement of the control rod 43 and the control link 44, resulting from the movementof the foot portion, will be compensated for by the pivotal joint at 45 between these parts, thus allowing the rod and link to assume an angular relation with each other, as indicated in dotted lines in Fig. 4. .In this position the backstop will prevent the calf portion from moving forwardly. When the wearer now moves hisbody so that the limb occupies the position shown in Fig. 2, his weight will be placed upon the toe portion of the foot and will cause the foot to be moved about its pivot in an opposite direction. This will cause the control rod 42 and the control link 44 to be pulled downwardly through the calf portion, which movement will cause the control lever to be voscillated about-its pivotal point 23.

Such movement wil cause the upwardly extend` all clearly shown in Fig. 5. When the parts just described have thus been operated, it will be obvious that the calf portion I6 will be free to swing rearwardly on its pivot pin I1 which is also clearly shown in Fig. 5 and also in dotted lines in Fig. 3. With the limb portions thus unlocked, the calf portion will naturally swing rearwardly as the wearer moves the thigh portion forwardly in the act of taking aforward step. In the act of swinging the calf Aportion forwardly, the resilient strap member 26, together with the momentum of the forwardly swinging calf portion.

;Will bring the limb portions in alignment with each other and the calf portion against the backstop to the position shown in Fig. 1 which corre-A sponds to the normally locked position of Fig. 4.

This position is assured by the fact that the weight of the wearer is placed upon the heel,

portion I5, calf portion i6, and foot portion I8"V Figs. 4-7, inclusive, and just above described. In

. formed in the backstop 55.

this form of invention, the backstop has its upper end mounted in a slot 5I formed in the thigh portion I5 and it is pivotally attached thereto by means of the pivot pin 24. The lower end of the backstop extends downwardly into the interior of the calf vportion I6. A .notch 56 is formed in the lower end of this stop for the engagement of a resilient strap 51, the sides of whichsex'tend upwardly, as shown in Fig.' 10. The ends 58 of this strap are passed through. suitable -openings formed in the back part of the calf portion where they are secured by suitable means. The lock latch 59, inthis form of invention, is in the form of a plunger 60 which is slidably disposed in a suitable aperture 6I The extreme rear end of this pin extends sufficiently beyond the back surface of the backstop to engage with the upper surface of the abutment 62 of the back part of the calf portion to act, together with the backstop, as a strut member to preventthe said portion from rotating on its pivot I1 in a backward direction. yThe forward end ofthe lock latch pin is provided with a pivot 63 which is lconnected by means .of a link 64 to the upper arm 31 'of a control lever 36, similar to the control lever of -the form of invention just above described. Like in the other form, this control lever .is attached to and mounted upon a pivot pin 23 carried by a stud 3 9. In this form, however, the forwardly extending arm 38 is connected to the heel 42 by two control rods 65 and 66, which are connected together at their adjacent ends by means of a 'control link 61.

These parts are pivotally connected together so that when the foot portion is moved bythe weight of the wearer upon the heel, the rods 65 and `66, together with the link 61, will berotated slightly at their pivotal connection so as to compensate for the upward movement of the heel without producing any further inward movement upon the plunger 60.

In this form of invention, as in the one just abovedescribed, the limb portions are always locked when brought in to alignment with each 'other and without any coaction of thejfoot portion. When the wearer, in thev act ofwalking,

'-to bear upon the toe thereof and thus the lplunger 66 of the lock latch will be drawn inwardly into the calf portion through the medium of the control rods 65 and 66, the ,control link 61, the control lever 36, and link 64. When thus drawn inwardly within the backstop 55,

the plunger will become. disengaged from 4the abutment 62, thereby allowing the calf portion to be swung backwardly upon its pivot I1. The cali portion is then free to be" swung in natural manner as the wearer takes a-forward step with the leg equipped with our invention. As the calf portion and thigh portion are relatively ro'- tated'to the position shown in` Fig. 9, as just above described, the parts will assume the positions shown in this figure. The helicalspring 48, which has one end attached to the calf portion through the medium of thev bolt 49 and its other end carried by the control lever, serves to force the-plunger outwardly into engageable position with the surface 62 or to the position shown 1in Fig. 8.of the drawings. In this position, the calf portion willv be locked to the thigh portion, remaining locked until after the forward step has been completed.

Reference is 'now to be had to the form.' of invention shown in Figs. 11 to 13, inclusive. In this form of invention, the thigh portion 10 is connected tothe calf portion 1I by means of a pivot 12 which is carried by the calf portion and vjournaled in the thigh portion. A foot portion I6 is provided in this form of invention which is substantially the same as the foot'portion of the other two forms above described. The backstop 13, in this form of the device, may be secured to the inside of lthe back part of the calf portion 1I byl means of abolt 14, as shown,

or if desired it may be so shaped as to extend against which the backstop is designed to engage to limit the forward swing of the caliportion.

The thigh portion and calf portion in .this

form of the invention are positively locked in the 'l positions shown in Fig. l11 where they are normally held in alignment by means of a strut member or supplemental wall portion 11, pivoted to a pin 16 which is carried by the thigh portion 10. Like in the other form of our invention, the limb portions are locked in alignment during the forward step and before the foot touches theground, thus insuring the wearer against acci:

dental collapse when he places his weight upon the foot portion. The lock latch 11 is mounted in a. slot 19 formed in the thigh portion and is provided with an abutting surface which is designed to engage the upper surface of the abutment 8I of the rear part of the calf portion when the parts are in the position shown in Fig. l1 to lock them in' such position. The 'strut member 4may be provided with a downwardly extending arm 82 which is connected to the upwardly extending arm 83v of the control lever 64 by means of a link 85. The control lever is pivotally mounted upon a pivot pin 86 carried by a stud 81, and is provided with va forwardly extending arm 88 which is connected to the heel 42 of the foot portion I6 by means of control rods 69 and 90 and a connecting control link 9|. A helical spring 92 is-provided for main-I taining the control lever and its-associated parts in the locked positions shown in Fig. 11. This spring has one of its ends attached to the arm 83 of the controLlever and its other end attached to a stud 93 carried by the rear part of the calf portion.

When the limb portions are in. their normally.

locked positions of alignment' and pressure is applied upon the toe part of the foot portion as, for instance, by the weight of the wearer, the control rods 69 and 96 and control link 9| will cause the control lever 64 to be moved to the position lshown in Fig. l2, in which position the surface '66 of the strut member will be withdrawn from its positive engagement with the v abutment 8| of the calf portionand moved inwardly toward the interior of the leg. As the calf portion is now swung with its pivot 12, the

' strut member will be moved down into the inother associated parts will assume the position shown in Fig. 12.

In this form of invention, momentum of the forwardly moving calf portion may be depended upon to bring the cali portion and thigh portion in .positions of alignment where the lock latch will come into engagement and lock these parts in the position shown in Fig. 11. However,

.if desired, the upper extending end 95 of the backstop 'i3 may be provided with a resilient strap St which is passed through a slot 9i formed in the thigh portion and which is secured to the outside at the iront of such' portion, whereby when the parts are rotated to the relative posi-.

' of the foot for producing the unlocking action by a push upon a slightly modied control lever instead of a pull, as shown in all of the forms illustrated. Furthermore, instead of having the foot portion pivotally attached to the calf portion, it is within the scope of oui invention to make the foot arigid or integral part of the calf portion and provide it with a button or lever which will operate' the control lever when the wearer places his weight upon the foot.

These and other modifications are within the scope of our invention and we do not, therefore,

wish to be limited to the exact embodiment herein shown and described, the forms shown being merely preferred embodiments of-our invention. Having thus described our invention, what we lclaim is:

1. .An artificial limb, comprising a thigh portion, a calf portion pivoted thereto, a. foot portion pivoted on said calf portion, a strut member pivoted on the thigh portion and engageable with an abutment on the rear` part oi the calf portion, a lever fulcrumed on a member carried by the `calf portion, a rigid link connecting said lever to the strut member to serve to push the latter into operative engagement with said abutment, a spring acting to move said strutymember, and a link connecting said lever to said foot portion to disengage said strut member against said spring.

2. An articial limb, comprising a thigh portion, a calf portion pivoted thereto, a foot portion pivoted on said calf portion, a strut member pivoted on said thigh portion and engageable with an abutment on said calf portion, a lever fulcrumed on the calf portion, a link connecting said lever to the strut member, a spring acting to move said strut member, and a link connecting said lever to said foot portion to disenga'ge said strut member against said spring.

3. An artiiicial limb, comprising a thigh portion, a calf portion pivoted thereto, a foot portion pivoted on said calf portion, said thigh and calf portions being formed with load-supporting abutments movable with said portions to `posi'- tions of alignment, a load-supporting strut mem.- xber normally disposed between said parts and acting under compression to support the load when said thigh and calf portions are in positions of alignment, means for urging said strut member to and yieldably holding it in load-supporting'positlon between said abutments when said thigh and-calf portions are aligned and irrespectivek of whether or not the weight of the wearer is upon said foot portion, and means connecting said strut member to said foot portion to remove said strut member from its load-supporting position.

4. An vartificial limb, comprising a thigh portion, a calf portion pivoted thereto, a foot portion pivoted on said calf portion, a load-supporting strut member carried by said thigh portion,

an abutment carried by the rear wall of said calf portion and normally engaged by said strut member, a spring for normally keeping said strut member in engagement with said abutment when said thigh and calf portions are aligned and irrespective of whether or not the weight of the wearer is upon said foot portion, a pivot for said strut member, said pivot being carried by and in the rear Wall of the thigh portion, and means connecting said strut member and said foot portion, whereby said strut member will be disengaged from said abutment against the tension of said spring by the weight of the wearer upon the toe of said foot portion.

5. An artificial limb, comprising a thigh portion, a calf `portion pivoted thereto, a foot portion pivoted on said calf portion, said thigh and calf portions being formed with load-supporting abutments movable with said portions to positions of alignment, a load-supporting strut member normally disposed between said parts and acting under compression to support the load when said thigh and calf portions are in positions of alignment, strut-removing means connectingsaid strut member with said foot portion to remove said strut member from its load-supporting position when Weight is placed upon the toe of said foot portion in the act of walking,` and single resilient means connected to and acting upon said strut-removing means for urging said strut member to and normally holding it in its load-supporting position and for urging said foot portion toward and returning it to neutral position, 4said strut-removing means including a plurality of pivotally connected links located between said foot portion and said strut member for operating the same, when said links are placed under tension, but permitting said foot portion to be restored to neutral position independent of the remaining parts of the strut-removing means when said links are placed under compression.

6. An artiiicial limb, comprising a thigh porl tion, a'calf portion pivoted thereto, a foot portion pivoted on said calf portion, said thigh and calf portions being formed'with load-supporting abutments movable with said portions to positions of alignment, a load-supporting strut mem- CHARLES E. s'rEEr-.n JAMES BECK.

Patent No, 2.170, 580.

CERTIFICATE' 0F CORRECTION.

Y August 22, 1959. 'CHARLES E. STEELE, E11-A1..

"It is hereby certified that error appears in tbe printed specification l of the above numbered patentrequiring correction as'follows: vPage 2, sec-. y ond column, line hl, for -"wil" read will; lpage 5, second column, line 58, `for lock latch read strut member or supplemental wail portiong' page )4, lfirxst column, lines and?, for "lock latch" read strut member; and that the said Letters Patent should be read with thisl correction' therein' that the same may confoz'm'to the record of the 'case in tnelPatent Office.

4Signed and sealed. this 26th day of' September, A. D. 1959,

Henry Van Arsdale,

(saai) Acting Ccnnnissioner of Patente." 

